Corrugated board bundler



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1s w r United States Patent 3,307,326 CORRUGATED BOARD BUNDLER Charles H. Krebs, Chicago, 11]., assignor, by mesne assignments, to Sunds Verkstader Aktiebolag, Sundsbruk, Sweden, a Swedish company Filed Apr. 21, 1964, Ser. No. 361,431 Claims. (Cl. 53-198) The present invention relates to an improved bundling machine for compressible sheets, particularly cardboard or paperboard box blanks. In the past, there have been attempts to bundle such blanks with gummed tape, dry tape, or the like, in order to retain a counted pile of knocked down corrugated containers in a package. Such methods and apparatus have not proved satisfactory, and the principal means employed for bundling corrugated boards to this day remains wrapping with twine in either one or two strings. The twine tie is rather unsatisfactory for many reasons. For one, it is relatively expensive since a multiply twine must be used on presently available commercial tying machines. Then, in addition, commercial machines are relatively slow and a typical machine will handle only 6 to 7 bundles per minute. Furthermore, the twine cuts into the blanks resulting in cut edges or flaps, or indented sides in the bundle.

The present invention deals with an apparatus for wrapping a paper tape around a bundle of compressible sheets such as corrugated carton blanks, and then adhesively securing the ends of the tape together along a preselected area of the bundle. There are many features of the apparatus involved in this development which will become apparent from succeeding portions of this description. However, at the outset, several of these features should be highlighted. For one, the adhesive seam on the bundle is provided at the trailing end of the bundle, so that it does interfere with the stacking of the bundles. Furthermore, the machine is capable of operating at bundling speeds substantially in excess of those achieved with twine tying machines. In addition, the apparatus of the present invention can make use of side rolls available at very low cost from paper manufacturers, where these trimmed edges from the cylinder machine are normally considered a waste product.

It is accordingly an object of the present invention to provide an improved apparatus for automatically binding together a bundle of compressible sheet material.

Another object of the invention is to provide a rapid automatic bundling machine which feeds a squared bundle of corrugated board or the like to a tying station where a paper tape is trained about the bundle and adhesively secured.

Another object of the invention is to provide an automatic bundling machine with a reciprocable knife structure.

Still another object of the invention is to provide an automatic bundling machine for corrugated board and the like which requires only a few simple adjustments to accommodate different sized bundles.

Another object of the invention is to provide an improved bundling apparatus which costs no more in terms of bundling costs than the twine tying machines presently in use, but provides substantially more satisfactory results.

A further description of the present invention will be made in conjunction with the attached sheets of draw- 3,307,326 Patented Mar. 7, 1967 ings which illustrate a particular embodiment of the invention.

In the drawings:

FIGURE 1 is a front elevational view of the bundling machine;

FIGURE 2 is a rear end elevational view of the apparatus of FIGURE 1;

FIGURE 3 is a fragmentary view in elevation illustrating the operation of the cutting and sealing portion of the assembly;

FIGURE 4 is a view similar to FIGURE 3 but showing the elements at the completion of the sealing operation; and

FIGURE 5 is a wiring diagram for the machine.

As shown in the drawings:

In FIGURE 1, reference numeral 10 indicates generally a bundling machine which embodies the novel features of the present invention. The machine 10 includes a pair of relatively small upright masts 11 and larger upright masts 12 secured to the machine floor 13. A cross arm 14 extending between the masts 11 and 12 carries a spindle 16 on which a roll 17 of strong paper tape is wound. The paper tape 18 unwound from the roll 17 may conveniently be a side roll of relatively heavy paper stock, available from paper manufacturers after trimming. The web of tape 18 is received about a roll 19, thence about a roll 21, the roll 19 being driven by means of a belt 22 from a motor 23 mounted on top of one of the masts 12. The web of tape is then received under a vertically movable dancer roll 24 which provides a proper tension to the web in its travel through the machine. After passing over an idler roll 26 the tape engages an edge folder 27 which folds the lateral edges of the tape inwardly to provide reinforced edges.

Turning now to the conveyor section of the apparatus, the conveyor mechanism is supported off the floor 13 by means of a frame 31 carrying a main drive motor 32 which drives a roller 33 by means of a chain 34. The conveyor itself, as best seen in FIGURE 2, consists of a plurality of flexible spaced belts, there being four bolts 36, 37, 38 and 39 being shown in the drawing. The belts 36 through 39 are supported on a shaft 41 received between opposed bearing members 42 and 43. Straightening means are provided at the inlet end of the conveyor for squaring up the four sides of a bundle to be wrapped with tapes. Straightening of the two sides of the bundle is accomplished by providing a series of rods 44 and 46 which depend from a pair of follower arms 47 and 48 respectively. The follower arms 47 and 48 threadedly engage doubly threaded screws 49 so arranged that rotation of the screws 49 causes the follower arms 47 and 48 to converge toward the center, so that the rods 44 and 46 engages the bundle deposited on the conveyor belts and straighten out the sides. The screws 49 are rotated by means of a pulley 51 driven by a motor 52 through a belt 53. e

The forward and trailing ends of the bundle are straightened through the combination of a gate mechanism at the forward end of the bundle, and pusher bars at the trailing end. The gate mechanism consists of a series of abutments 54 pivotally mounted at a pivot genenally indicated at numeral 56 and located between the spaced belts 36 to 39 inclusive. The bundle is confined between these abutments 54 and a plurality of spaced pairs of pusher bars 56 and 57 secured to the belts 37 and 38.

After the bundle has been straightened on all four sides, it is advanced by means of the conveyor to a wrapping station which is best illustrated in FIGURES 3 and 4 of the drawings. As it advances into the wrapping station, it comes into contact with a paper tape 18 which has been positioned across the line of travel of the bundle, in a plane normal to the line of travel. An end portion of the tape measuring a few inches or so is confined within a gripping means consisting of a pair of jaws 61 and 62 operated by an air cylinder 63. The paper tape 18 is fed to the jaws by passing it through the nip of a pair of cooperating rollers 64 and 65 which also crease the previously folded over edges of the tape 18. The roller 65 is mounted on a pivotal arm 66 whose movement is controlled by an air cylinder 67 (FIGURE 1). The roller 66 is driven through a chain 68 from a motor 69 secured to the cross member 14. Thus, when the air cylinder 67 is operated to pivot the roller 65 into engagement with the driven roller 64, the tape 18 is fed between the nip of the rolls and into the jaws 61, 62 of the releasable gripping device.

At the time a bundle 71 is in the wrapping station, it is subjected to a compressive force by means of a floating compression unit 72 whose vertical position can be adjusted by means of a hand wheel 73 to compensate for different sized bundles. The compression applying elements include a pair of laterally spaced belts 74 carried about a series of rollers 75, '76, and being provided with resiliently biased rollers 77 supported on arms 78, the rollers 77 hearing down upon the lower run of the belt 74 to keep the bundle 71 under compression during binding of the bundle and subsequently until such time as the adhesive has set and the compressive force can be released.

FIGURE 3 of the drawings illustrates the method in which the tape 18 is trained around the bundle 71, and provided with a sealed overlap seam on the trailing end of the bundle 71. In advancing to the sealing station, the forward edge of the bundle first contacts the tape 18, and the bundle is moved to a position in which the for ward end, the top, and the bottom of the bundle 71 are covered with the tape 18, as illustrated in the full line portions of FIGURE 3. Then, a reciprocating knife mechanism 81 including a laterally movable knife blade 82 operated by a pneumatic cylinder 83 cuts the tape after it is moved downwardly to a position corresponding to that shown in the dotted outline of FIGURE 3. Concurrently therewith, the jaws 61 and 62 of the gripper mechanism release and an adhesive applicator roller 84 mounted on a rod 85 and operated from an air cylinder 86 applies a layer of adhesive such as a quick setting glue to the few inches or so of the tape 18 previously held within the jaws 61 and 62. The roller also presses the end portion 87 of this tape against the trailing end of the bundle '71. Adhesive is applied to the applicator roller 84 from a roller 88 partly immersed in an adhesive fountain89 and slowly rotated therein by means of a motor (not shown). In its retracted position, the movement of the roller 88 against the applicator roller 84 applies a thin uniform film of the adhesive to the applicator roller 84.

After the applicator roller 84 has applied the adhesive and pressed the end portion 87 of the tape against the bundle 71, the severed end of the tape 18 is lapped over the end portion 87 as best illustrated in FIGURE 4 by continued downward movement of the reciprocating carriage 81. A roller 91 located at the bottom of the carriage 81 serves to apply pressure to the seam provided by the overlapping end portions of the tape 18. Simultaneously, the jaws 61 and 62 have been opened and a further supply of tape 18 is fed therein to provide for commencing the next cycle of operation. When the jaws 61 and 62 close upon the tape 18, the various mechanisms involved are reset and the main conveyor is again actuated to move the wrapped bundle to a second station where it is still under compression from the rollers 77. The bundle stays at this second station while a second bundle is wrapped and sealed in the same manner, giving the initially wrapped bundle a few more seconds dwell time so that the adhesive is thoroughly bonded for release of the compressive force on the compressible bundle. Then, the wrapped bundle may be removed by means of a take-off belt 93 driven by a motor 94.

The air cylinder which actuates the reciprocating carriage 81 has a substantial stroke, as best illustrated in FIGURE 2 of the drawings. The assembly includes a rod 96 which carries a switch operating cam 97 arranged to sequentially engage a plurality of switches, three of which, switches 98 to 100 inclusive are shown in FIG- URE 2. These switches have operating arms 101, 102 and 103 respectively which are operated by engagement with the camming surface 97 in a sequence which is about to be described.

Referring to the wiring diagram of FIGURE 5 it will be seen that the system is actuated from the secondary 106 of a transformer 107 having primary windings 108 connected across a three phase alternating current system, or suitable source of power. A stop button 109 and a start button 110 are in series with a relay contact 111 in the line which energizes the main drive motor 32. In parallel with the start button 110 is a pair of relay contacts 112 and 113 operated by a paper feed motor 69 and the motor 94 at the discharge end of the conveyor, respectively. Upon closing of a relay contact 114, the reversible motor 52 of the straightening mechanism is also actuated, the motor having an armature 115 and field coils 116 and 117. The motor 52 is driven selectively in either the forward or reverse direction by the actuation of a pair of relay contacts 118 and 119 in the field circuits.

The paper feed motor 23 at the top of the mast 12 is actuated through a line which includes a limit switch 121 operated by the dancer roll 24.

A cycle start button 122 is disposed in parallel to a limit switch 123 disposed at the inlet end of the conveyor, and actuated by placing a bundle of material to be wrapped on the conveyor. Closing of either of these switches energizes a relay coil 124 through a normally closed relay contact 125. Energization of the relay coil 124 also serves to close a normally opened relay contact 126 to serve as a holding contact. At the same time, the relay contact 114 is closed, thereby energizing the reversible motor and commencing operation of the lateral straightening mechanism.

Reversal of the motor 52 and retraction of the followers 47 and 48 is accomplished by means of a circuit including a traversing switch 127 located on the carriage which energizes a relay coil 128 through a normally closed relay contact 129. Energization of the relay coil 128 operates a holding contact 130 and also changes direction of rotation of the motor 52 by reversing the energization of the fields through the contacts 118 and 119.

A relay coil 131 which controls the operation of the contacts 125 and 129 is energized by a limit switch 132 situated such as to be engaged by the followers 47 and 48 on their return stroke. Upon energization of the relay coil 131, a holding contact 133 is also energized. Energization of the relay coil 131 thereby deenergizes the reversing motor 52 since it deenergizes the circuits to the relay coils 124 and 128.

Energization of the relay coil 131 also closes a normally open relay contact 134 which is in series with a second relay contact 135 to energize a solenoid operated valve 136. This valve retracts the gate mechanism by pivoting the abutments 54 about their pivot 56 so that they disappear between the spaced conveyor belts 36, 37, 38 and 39.

A relay coil 137 is energized by either a conveyor start button 138 or a limit switch 139 operated by the drop ping of the gate mechanism. Upon energization, the relay coil 137 closes a holding contact 140 and also the relay contact 111 in the energizing'circuit for the main drive motor 32, thereby starting operation of the conveyor.

The conveyor belts carry dogs which engage a limit switch 141 on the frame shortly before the bundle is advanced to the wrapping and sealing station. Upon closing of the switch 141, relay coil 142 is energized. However, the switch 141 has a built in time delay to make sure that the bundle has come to a complete stop at the wrapping and sealing station before the remainder of the mechanism is operated. Energization of the relay coil 142 operates a holding contact 143 in parallel with the switch 141. Energization of this relay coil also serves to open contact 144 in the energizing line to the relay coil 131. Energization of the relay coil 142 also serves to open a contact 145 in the energizing circuit to the relay coil 137, thereby opening the contact 111 and deenergizing the main drive motor 32.

When the relay coil 142 is energized, it also closes a contact 146 which operates a solenoid operated valve 147 controlling operation of the air cylinder which reciprocates the reciprocating knife cutting carriage 81. This operation initiates downward movement of the reciprocating carriage, and sequential engagement of the various cam operated switches. Energization Of the relay coil 142 closes a switch contact 148 which actuates a solenoid operated valve 149 when a limit switch 150 is closed. This limit switch 150 controls operation of the glue applicator roll 84. Upon energization of the valve 149, the air cylinder 86 is actuated to raise the glue applicator 84 to be in position to apply an adhesive layer to the paper tape 18.

Energization of the relay coil 142 also closes a contact 151 to energize a solenoid operated valve 152, thereby releasing the gripping mechanism since the valve 152 controls the operation of the air cylinder 63. The end por tion of the tape 87 being held between the jaws 61 and 62 is thereupon released, and folded back against the trailing end of the bundle 71 by the upward movement of the glue applicator roll 84.

The first switch to be operated by downward movement of the reciprocating carriage is switch 98, as illustrated in FIGURE 2. Upon energization of this switch, a solenoid operated valve 53 is actuated to operate the air cylinder 83 associated with the cutting knife 82. Then, continued downward movement of the main piston assembly actuates the switch 99 which thereupon energizes a solenoid operated valve 154 which, in turn, actuates the air cylinder 67, pivoting the roller 65 against the paper tape so that it may be fed into the open jaws of the gripping mechanism, as shown in FIGURE 4.

The feeding of the tape end to the jaws 61 and 62 also serve to energize an electric eye 155 which controls the operation of a switch 156. Upon closing of the switch 156, a relay coil 157 is energized thereby opening a normally closed contact 158 in the energizing line to the valve 154, thereby terminating feed of the paper strip into the jaws. Energization of the relay coil 157 also serves to close a relay contact 158, thereby applying an energizing voltage across a relay coil 159. At energization of the coil 159, a holding contact 160 is closed. The energization of the relay coil 159 serves to open a normally closed relay contact 161 and thereby deenergize the relay coil 142. When this happens, the reciprocating carriage 81 is moved upwardly, all the relays are reset, and the machine is ready for another cycle of operation.

From the foregoing, it will be understood that the method and apparatus of the present invention provide an automated system for wrapping a stack of compressible sheets such as corrugated boards. The bundles are secured by a paper band having reinforced, folded edges tight on the bundle, and joined at the trailing end of the bundle. Since the band is quite tight, there is normally no need for more than one band on any bundle in the usual sizes. It should also be understood that various modifications can be made to the described embodiments without departing from the scope of the present invention.

I claim as my invention:

1. A bundling machine for cardboard and the like comprising a conveyor means, paper tape supply means arranged to feed a paper tape, releasable gripping means positioned to hold the end of said tape normal to the direction of movement of said conveyor means, drive means propelling a bundle on said conveyor means into engagement with said tape while so held by said gripping means, means stopping the movement of said conveyor means after said bundle has moved to a position in which said tape has engaged the forward end, top, and bottom of said bundle, adhesive applicator means cooperating with said gripping means to apply adhesive to the end of said tape, a carriage movable relative to said gripping means for applying tape to the trailing end of a bundle, means on said carriage for severing said tape, and means on said carriage for pressing the severed end of said tape into engagement with the adhesived end of said tape at the trailing end of said bundle.

2. The machine of claim 1 which also includes edge folding and creasing means for-said tape between said supply means and said releasable gripping means.

3. The machine of claim 1 which also includes adjustable compression means arranged to apply pressure on said bundle while the adhesived tape is being applied, and to maintain compression on said bundle until said adhesive has set.

4. A bundling machine for cardboard and the like comprising a plurality of spaced conveyor belts, straightener means movable laterally inwardly with respect to said belts to straighten the sides of a bundle disposed on said conveyor, a gate having abutments extending between said belts, spaced pusher bars carried by said belts, said pusher bars cooperating with said abutments to straighten the leading and trailing edges of said bundle, paper tape supply means, releasable gripping means positioned between a pair of said belts to hold the end of said tape normal to the direction of travel of said belts, said conveyor belts being arranged to propel said bundle into engagement with said tape while so held by said gripping means, means stopping the movement of said conveyor belts after said bundle has moved to a position in which said tape has engaged the forward end, top and bottom of said bundle, adhesive applicator means cooperating with said gripping means to apply adhesive to the end of said tape, a carriage movable relative to said gripping means for applying tape to the trailing end of a bundle, means on said carriage for severing said tape, and means on said carriage for pressing the severed end into engagement with the adhesived end of said tape at the trailing end of said bundle.

5. The machine of claim 4 which alsoincludes folding and creasing means for said tape between said tape supply means and said releasable gripping means.

6. In a bundling machine, a sealing and cutting mechanism comprising releasable gripper means operable to hold an end of a tape, a carriage movable vertically relative to said gripper means, knife means carried by said carriage and arranged to slit said tape transversely, an adhesive applicator roller vertically movable relative to said gripper means and positioned to apply adhesive to the tape end being held by said gripper means, and roller means on said carriage for pressing the severed tape against the adhesive tape end.

7. In a bundling machine for cardboard sheets and the like, a plurality of spaced conveyor belts arranged to support a bundle of said sheets, gripping means releasably holding a paper tape across the path of travel of said bundle, means for advancing said bundle to a sealing position in which said tape covered the forward end, top, and bottom of said bundle, resiliently biased pressure means applying a compressive force to said bundle in said position, an adhesive applicator roller movable vertically with respect to said gripping means and arranged to apply an adhesive coating to said tape, a carriage movable relative to said gripping means for applying tape to the trailing end of a bundle, means on said carriage for severing said tape, and means on said carriage for pressing the severed tape against said adhesive coating.

8. The machine of claim 7 in which said reciprocable cutting means delivers the severed end of said tape to said gripping means.

9. The machine of claim 7 in which said resiliently biased pressure means is adjustably positionable with respect to a bundle of said sheets.

10. The machine of claim 7 including means for fol-ding over the lateral edges of said tape before insertion into said gripping means.

References Cited by the Examiner UNITED STATES PATENTS 2,502,374 3/1950 Gilowitz 53--198 2,842,915 7/1958 HoWatt 53198 X 3,000,151 9/1961 Winkler et a1. 533

FRANK E. BAILEY, Primary Examiner.

R. I. ALV'EY, Assistant Examiner. 

6. IN A BUNDLING MACHINE, A SEALING AND CUTTING MECHANISM COMPRISING RELEASABLE GRIPPER MEANS OPERABLE TO HOLD AN END OF A TAPE, A CARRIAGE MOVABLE VERTICALLY RELATIVE TO SAID GRIPPER MEANS, KNIFE MEANS CARRIED BY SAID CARRIAGE AND ARRANGED TO SLIT SAID TAPE TRANSVERSELY, AN ADHESIVE APPLICATOR ROLLER VERTICALLY MOVABLE RELATIVE TO SAID GRIPPER MEANS AND POSITIONED TO APPLY ADHESIVE TO THE TAPE END BEING HELD BY SAID GRIPPER MEANS, AND ROLLER 